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Discussion Starter #1
I've been working on this build for the last month or so, so pictures will come pretty quickly at first and then will taper off a bit as I move forward. I'm trying some install approaches that are new for me, and not all that common, so I had planned to wait until I heard the system before posting...but boring days at work thanks to rain have left me wanting to share. :D Where I am and what I'm trying isn't really groundbreaking stuff, but I am trying to draw from what I've learned and experienced in this build to have it, hopefully, be my best system to date.

I decided to complete this build in my wife's Murano for a couple of reasons. First, she told me that she wanted a good stereo after hearing mine (so I blame her for all of this ;)). Second, this is our primary car. I have a company truck, and aside from her driving my Maxima while I've been doing this, my car has only been driven three times since March (so why use my car for the "good stuff"). Third, I feel I've learned a good bit as I've progressed, and I was excited about getting a "fresh start" with her car instead of modifying my modified install.

I plan to compete with this car in both Modex and SQ2+, but it's a family car first. That means I had some "rules" to work with. I cannot cut metal (in the kicks, the doors, or anywhere else), I cannot leave anything non-functional, I cannot remove the spare tire, and I cannot have any part of the trunk sitting higher than it does from the factory. The good news...I can cut the dash! I got "permission" for this since I can replace it for $150-200 on e-bay.

Gear:

Source--OEM Unit
Processor--JBL MS8 (running 5.1)
Front Midbass--JBL 660GTi
Front Midrange/Tweeter--Aurasound Whisper (2 per channel)
Rear-Fill--Aurasound Whisper (2 per channel)
Subs--JBL 1000GTi (x2)
Amp #1--JL HD600/4 (front left and right)
Amp #2--JL HD900/5 (center and subs)

I plan to have the front stage up and running before Christmas (which means before the week has closed :eek:), so I probably won't update anything at night just because I'll be busting it out in the garage.
 

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Discussion Starter #3 (Edited)
So, with any good tale...we start at the beginning. I had begun to develop the feeling that reflections from higher frequency information (those primarly covered by tweeters) were both the most common problems for listening fatigue and lack of width. My plans and research for this install centered around reducing this. I enjoyed reading the "one tweeter" thread from PB and decided to build my pod around his design in the thread. One that used waveguides to narrow directivity (to avoid reflections) and still keep good levels of output as upper-end response dropped. The plan was to use Aura Whispers for the center from midrange and up, a JBL 500GTi for center midbass, dual c508GTi's in the doors for left and right midbass, and to put some OS JBL 404GTi's in the corner of the dash firing into the glass (since I LOVE the GTi stuff and they have the tweeters braxially mounted) for left and right midrange and up. My plans changed very early after this, but the waveguide/directivity plan stuck, and so this was my "starting point".

Here is a link to the thread I'm referencing: http://www.diymobileaudio.com/forum/diyma-sq-forum-technical-advanced/72891-anyone-tried-using-one-tweeter.html

Here is PB's pod:



Here is as far as I got with mine before going in a slightly different direction:



Here is the templete (that I still used) for the dash and the original planned layout:

 

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Discussion Starter #4
At this point I'd like to say a particular thank you to Erin (bikinpunk) and Todd (highly). We three had many discussions as I started working on this build and as it progressed. All of the work you will see was done by me, and nearly all of the ideas were "mine" too, but they were an invaluable "sounding board" for those ideas, gave valuable input that steering me when at an either/or point, and kept me motivated as I shared some of the pictures you will see.

There are others I will thank throughout this build. Some because they helped me get certain pieces I needed, and some because I built off of the information they shared here. I will say now though, that I appreciate the quality posts of this forum and the kind members I have met along the way.

So...enough with being all gushy and back to the build.

I decided that I wanted my front stage to have the same "tonality" across the board. You can argue that it won't matter much in the midbass and I might agree, but running tweeters for left and right and dual Whispers for the center just didn't seem like it would sound natural to me. I "needed" the whispers for my center pod, so I decided to use them for left and right as well.

Even though I'm not going in the same direction, or using the same method of control, this part of the plan was equally inspired by Mark E.'s NASCAR (from discussions with Todd) and his use of arrays and with PB's "one tweeter" thread. The plan was to use multiple 2" drivers to: spread the sound around for a 2-seat setup, increase the output, and use a 2" driver so I didn't lose too much top-end compared to traditional wideband setups. The plan was to use waveguides to: keep the "spread" from hitting the glass above 2khz or so and to help amplify everything above 2khz to help fight the drooping respose.

In this picture, the red shows the planned "beams" and the yellow shows the wider dispersion. The bottom image show how the drivers on the left and right would be slightly offset so the "beams" didn't "hit" each other and cause terrible comb-filtering.*

* I did my best to change CTC spacing slightly and adjust pod height slightly to make sure primary comb-filtering didn't cascade and give me a null that was too big.

 

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That's a very interesting setup you have planned for your front stage....good luck with it and I hope it works out for you
 

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Discussion Starter #7
sub'd.

Thought it would be a year until this log was posted.... ;)
Everybody else (you, Todd, Kirk) has been so transparent with what they have in their build...I thought I would follow suit. :) I really just wanted to make sure it worked like I hope/plan for it to, but impatience got the best of me.
 

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how big are those whisper drivers, will three of them fit in the space of a standard din slot? and output wise can they do loud and clean? or do they start to frizzle at higher output. I'm not looking for SPL loud, but rather loud with the windows down doing 80...
 

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Discussion Starter #9
So, my last post showed what I had initially planned for the build. Those plans changed, but the premise remained. To eliminate as many reflections as possible and reflections that couldn't be eliminated would be "treated" the best they could. "Treated" implies the use of crossover points that avoid massive comb-filtering and baffles that blend as smoothly as possible with surroundings (and to have roundovers to reduce diffraction when a smooth transition isn't possible).

I also decided that I wanted to put all of the speakers on the dash. Left, right, and center midbass would be going up top firing into the glass. This is a first for me, and I was concerned about how it may affect width and depth. The midbass will sit in front of the pods, but it's the part I'm still most concerned about until I hear it in action, but I had some logic behind the decision. I plan to cross the midbass to midrange somewhere between 350-500hz/24db (I plan to start with 400hz and work from there). Each midbass is less that 7" from it's pod and less than 7" from the glass. Based on 1/4 wave theory, this SHOULD put the first potential null around 500hz and SHOULD also allow me to treat each set of drivers as a single "source" below 500hz. Where hope comes into play is that the "source" will move back to the pods and not forward to the midbass.

For those that love pictures...they will be in the next update. ;)
 

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Discussion Starter #10
how big are those whisper drivers, will three of them fit in the space of a standard din slot? and output wise can they do loud and clean? or do they start to frizzle at higher output. I'm not looking for SPL loud, but rather loud with the windows down doing 80...
They are 2" nominal but actually a bit smaller. You can find them on the Madisound website and Zaphaudio has some test data on them in his tidbits section. If I were to use a single driver, I don't think I could get the output I want. With two placed in a partial waveguide I was able to get enough output from them without distorting that I decided to move forward with this build (I tested them on a baffle in my home theater).

As far as fitting them in a single din section, it would be a tight fit. You would probably have to trim the flange down a bit to make it work, but I think it could be done.
 

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Discussion Starter #11
I decided to start with the "easy" part first in my build which was cutting the midbass baffle and working on the center pod.

Template for baffle:



Transferred to MDF:



After a steady hand on the bandsaw:



Kerfed board to follow contour of baffle (this is actually from my "rejected" pod, but I don't have a picture of the other):



Gluing down the "lid" after putting a 45-degree chamfer down for the "waveguide":



Some pictures of the pod after I put a roundover on all corners:







In the living room for listening impressions:

 

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Discussion Starter #13
The left and right pods were much more difficult to pull off. I wanted the to blend with the glass, the dash, and the pillars. I wanted them to follow the contour of the dash (see drawing above). To figure the shape, I used the tried and true method of trimming carboard until it fit. Using some aluminum foil to hold the curves at the pillar helps here. After I had the shape, I needed to decide on how to make the curve. I considered kerfing and steam bending (the first method uses mdf the second MUST NOT use mdf :D). I finally settled on using some 1/4" ply I had lying around and "cold bending" the wood. This method uses a negative shape to form the bend and glue to hold the pieces together.

Here are the cutouts, still flat, getting the holes routed and chamfers added:



Here is the negative I'll be using:



First baffle getting "glued and screwed...err...clamped":





Does it work???





It DOES!!! So we repeat for the passenger side:



To get the initial fitment, I just put a 45 on all sides. It isn't perfect, but I can work with that:



 

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Discussion Starter #15
Now that I've satisfied some of the picture hungry people, I'll get back to the waveguide decision a bit.

Why was 2khz chosen? Simply because it was the lowest I could go, in the room I had, with the drivers I chose to use. As frequency goes down, waveguides get larger. As driver diameter gets smaller, waveguides get larger (the waveguide for the tweeter in the JBL 660GTi set is 4"x6"). With a 2" driver, I needed a 3" total diameter waveguide to get down to 2khz. I had a 1" thick baffle and the Whisper mounts from the back with a 1/2" face depth. With that remaining 1/2" baffle thickness, I could use a 45-degree chamfer to get a 3" total diameter (for 2khz directivity control).

Concerns were also shared that the MS8 doesn't play nice with horns. Here are my thoughts on it from a PM:

See, waveguides are waveguides and horns are horns. They are similar (and somewhere along the way started to get lumped together) but they are not the same. They both attempt to control directivity and increase output. A horn has lots of diffraction and reflection going on as it travels down the throat to a rectangular mouth. This leads to a very uneven frequency response, but it is also what helps give horns the peaky/"lively" response people love. The MS8 tries to even that out and it doesn't seem to work well. A waveguide, on the other hand, tends to retain a smooth frequency response and reduce diffraction. I'm using it to limit reflections off the glass and boost the wideband drivers falling frequency response. It only works from 2khz up. The baffles in the build are designed to blend smoothly with all the other boundaries to HOPEFULLY reduce issues below 2khz.
 

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Discussion Starter #16
Now that the baffles were all made, I was ready to see how it would look in the car. No part of the dash was cut at this point, so the big baffle is sitting around 3/4" higher than it will in it's final position. Since my cell phone doesn't have a wide-angle lens, I had to put the camera by the ceiling from the back seat to get this shot. I share that because visibility is MUCH better than it appears in this photo.

 

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Discussion Starter #17
I couldn't go any further in the build at this point without putting the dremel to the dash...

...so I did...

...and found...

DASH VENTS!!! :mad:



Since I had already cut the dash, I decided to worry about it later and keep going.



Until I had this:



At least the baffle fits :rolleyes::

 

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Discussion Starter #19
Just curious, but do you think its legal to drive with those on the dash? I ask as they say a crack in the window is enough to cause an obstruction to your view to be illegal to drive with.
I'm not entirely sure honestly. I can tell you that the center pod is less of an obstruction than the hoodline itself (i.e. you can still see the hood past the pod). The left and right pods also only block around 1-2" of true visibility from the corners of the dash. This doesn't affect blind spots at all and would only POSSIBLY make parking in tight corners or reading mailbox numbers a bit more difficult.

I will counter that pillar gauges/center stack gauges/pillar tachs in sport cars and midrange pillar pods all block visibility more than my setup does.

I was still concerned about this and had both my wife, who is 5'-2", and father, who is an engineer for Nissan, give me their "OK" before moving forward.
 

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I'm not entirely sure honestly. I can tell you that the center pod is less of an obstruction than the hoodline itself (i.e. you can still see the hood past the pod). The left and right pods also only block around 1-2" of true visibility from the corners of the dash. This doesn't affect blind spots at all and would only POSSIBLY make parking in tight corners or reading mailbox numbers a bit more difficult.

I will counter that pillar gauges/center stack gauges/pillar tachs in sport cars and midrange pillar pods all block visibility more than my setup does.

I was still concerned about this and had both my wife, who is 5'-2", and father, who is an engineer for Nissan, give me their "OK" before moving forward.
Like I said I was just curious, as I got a FX35 and was looking at what I can do with the dash, but didnt come up with much as the visibility out the front is kinda scarce compared to other cars.

But I like the progress so far and I am curious as to how it will turn out for ya.
 
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